Zobrazeno 1 - 10
of 38
pro vyhledávání: '"Dehimi, Souheyb"'
In this article, we give conditions guaranteeing the commutativity of a bounded self-adjoint operator with an unbounded closed symmetric operator.
Comment: arXiv admin note: substantial text overlap with arXiv:2201.10604
Comment: arXiv admin note: substantial text overlap with arXiv:2201.10604
Externí odkaz:
http://arxiv.org/abs/2203.07266
In this paper, we prove and disprove several generalizations of unbounded versions of the Fuglede-Putnam theorem.
Comment: arXiv admin note: substantial text overlap with arXiv:2201.10604
Comment: arXiv admin note: substantial text overlap with arXiv:2201.10604
Externí odkaz:
http://arxiv.org/abs/2203.06715
Publikováno v:
In Journal of Mathematical Analysis and Applications 1 November 2024 539(1) Part 2
In this article, we prove and disprove several generalizations of unbounded versions of the Fuglede-Putnam theorem. As applications, we give conditions guaranteeing the commutativity of a bounded self-adjoint operator with an unbounded closed symmetr
Externí odkaz:
http://arxiv.org/abs/2201.10604
In this paper, we give conditions forcing nilpotent operators (everywhere bounded or closed) to be null. More precisely, it is mainly shown any closed or everywhere defined bounded nilpotent operator with a positive (self-adjoint) real part is automa
Externí odkaz:
http://arxiv.org/abs/2008.09509
We show that a densely defined closable operator $A$ such that the resolvent set of $A^2$ is not empty is necessarily closed. This result is then extended to the case of a polynomial $p(A)$. We also generalize a recent result by Sebesty\'en-Tarcsay c
Externí odkaz:
http://arxiv.org/abs/2007.14349
Let $n\in\mathbb{N}$ and let $A$ be a closed linear operator (everywhere bounded or unbounded). In this paper, we study (among others) equations of the type $A^*A=A^n$ where $n\geq2$ and see when they yield $A=A^*$ (or a weaker class of operators). I
Externí odkaz:
http://arxiv.org/abs/1902.02193
In this paper, we show a new and classic version of the celebrated Fuglede Theorem in an unbounded setting. A related counterexample is equally presented. In the second strand of the paper, we give a pair of a closed and self-adjoint (unbounded) oper
Externí odkaz:
http://arxiv.org/abs/1901.09271
In this paper, we give an example of a closed unbounded operator whose square's domain and adjoint's square domain are equal and trivial. Then, we come up with an essentially self-adjoint whose square has a trivial domain.
Comment: 04 pages
Comment: 04 pages
Externí odkaz:
http://arxiv.org/abs/1808.09523
The primary purpose of the present paper is to investigate when relations of the types $|AB|=|A||B|$, $|A\pm B|\leq |A|+|B|$, $||A|-|B||\leq |A\pm B|$ and $|\overline{\text{Re} A}|\leq |A|$ (among others) hold in an unbounded operator setting. As int
Externí odkaz:
http://arxiv.org/abs/1804.00899